Site of Katsumoto Castle
The hilltop Katsumoto Castle was a hastily built and short-lived citadel intended for use by the warlord Toyotomi Hideyoshi (1537–1598) during an invasion of the Korean Peninsula. Having completed the unification of Japan under his rule, the ambitious Hideyoshi next set his sights on conquering Ming China by way of Korea. The expedition was to invade Korea via Iki and Tsushima, and Hideyoshi ordered his lieutenants to construct bridgeheads on the islands for a force of 150,000. Each of these bases, including the one in Katsumoto on the northern edge of Iki, was to include a castle from which Hideyoshi could personally oversee the campaign.
Hideyoshi’s generals built Katsumoto Castle in only four months in 1591. The fortress centered on an oval area measuring 90 by 40 meters that was 80 meters above sea level, overlooking a cove where the expeditionary force would anchor its ships before crossing to Tsushima. Hideyoshi’s poor health prevented him from traveling, and the invasion ended in failure. In the early 1600s, the Tokugawa shogunate restored diplomatic relations with Korea and had Hideyoshi’s castles on Iki and Tsushima decommissioned as a gesture of peace.
The site of Katsumoto Castle is now a park with a view over the village and port of the same name. All that is left of the castle today are the entrance and some of the ramparts that surrounded the main keep. The remaining ramparts are largely intact except for the corners, where watchtowers would have stood. Removing the corner stones was an often-employed way of making a castle defensively useless without having to demolish the entire structure.